1. Field
The following description relates to a codebook that is used in a multiple input multiple output (MIMO) communication system.
2. Description of the Related Art
A number of researches are being conducted to provide various types of multimedia services such as voice services and to support high quality and high speed of data transmission in a wireless communication environment. Technologies associated with a multiple input multiple output (MIMO) communication system using multiple channels are in rapid development.
In a MIMO communication system, a base station and terminals may use a codebook in order to appropriately cope with a channel environment. A particular space may be quantized into a plurality of codewords. The plurality of codewords that is generated by quantizing the particular space may be stored in the base station and the terminals. Each of the codewords may be a vector or a matrix according to the dimension of a channel matrix.
For example, each of the terminals may select a matrix or a vector corresponding to channel information from matrices or vectors included in a codebook, based on a channel that is formed between the base station and each of the terminals. The base station may also receive the selected matrix or vector based on the codebook to thereby recognize the channel information. The selected matrix or vector may be used where the base station performs beamforming or transmits a transmission signal via multiple antennas.
Accordingly, there is a need for a well-designed codebook in order to improve a performance of a MIMO communication system.